Parenteral delivery of various drugs, i.e., delivery by means other than through the digestive track, has become a desired method of drug delivery for a number of reasons. This form of drug delivery by injection may enhance the effect of the substance being delivered and ensure that the unaltered medicine reaches its intended site at a significant concentration. Similarly, undesired side effects associated with other routes of delivery, such as systemic toxicity, can potentially be avoided through parenteral delivery. By bypassing the digestive system of a mammalian patient, one can avoid degradation of the active ingredients caused by the catalytic enzymes in the digestive tract and liver and ensure that a necessary amount of drug, at a desired concentration, reaches the targeted site.
Traditionally, manually operated syringes and injection pens have been employed for delivering parenteral drugs to a patient. More recently, parenteral delivery of liquid medicines into the body has been accomplished by administering bolus injections using a needle and reservoir, continuously by gravity driven dispensers, or via transdermal patch technologies. Bolus injections can imperfectly match the clinical needs of the patient, and may require larger individual doses than are desired at the specific time they are given. Continuous delivery of medicine through gravity-feed systems compromises the patient's mobility and lifestyle, and limits the therapy to simplistic flow rates and profiles. Another form of drug delivery, transdermal patches, similarly has its restrictions. Transdermal patches often require specific molecular drug structures for efficacy, and the control of the drug administration through a transdermal patch is severely limited.
Ambulatory infusion pumps have been developed for delivering liquid medicaments to a patient. These infusion devices have the ability to offer sophisticated fluid delivery profiles accomplishing bolus requirements, continuous infusion and variable rate delivery. These infusion capabilities usually result in better efficacy of the drug and therapy and less toxicity to the patient's system. Currently available ambulatory infusion devices are expensive, difficult to program and prepare for infusion, and tend to be bulky, heavy and very fragile. Filling these devices can be difficult and require the patient to carry both the intended medication as well as filling accessories. The devices often require specialized care, maintenance, and cleaning to assure proper functionality and safety for their intended long-term use, and are not cost-effective for patients and healthcare providers.
As compared to syringes and injection pens, pump type delivery devices can be significantly more convenient to a patient, in that doses of the drug may be calculated and delivered automatically to a patient at any time during the day or night. Furthermore, when used in conjunction with metabolic sensors or monitors, pumps may be automatically controlled to provide appropriate doses of a fluidic medium at appropriate times of need, based on sensed or monitored metabolic levels. As a result, pump type delivery devices have become an important aspect of modern medical treatments of various types of medical conditions, such as diabetes, and the like.
While pump type delivery systems have been utilized to solve a number of patient needs, manually operated syringes and injection pens often remain a preferred choice for drug delivery as they now provide integrated safety features and can easily be read to identify the status of drug delivery and the end of dose dispensing. However, manually operated syringes and injection pens are not universally applicable and are not preferred for delivery of all drugs. There remains a need for an adjustable (and/or programmable) infusion system that is precise and reliable and can offer clinicians and patients a small, low cost, light weight, simple to use alternative for parenteral delivery of liquid medicines.
There is a strong market demand for drug delivery devices which are easy-to-use, cost-efficient, and which include integrated safety features. However, manufacturing of such devices can be cost intensive, which results in higher costs to patients. Much of the manufacturing costs can be attributed to the need to maintain a sterile fluid pathway from the drug container to the needle, prior to introduction of the drug to the patient. Some commercial products seek to maintain the sterility of the device by manufacturing the components in a non-sterile environment and then sterilizing the entire device. A recognized downside of such processes is the need to separately fill the drug container after the device sterilization, but prior to drug injection, as most pharmaceutical compounds are not capable of withstanding the device sterilization process. Alternatively, the drug delivery device may be manufactured as a pre-filled device, wherein the device is filled with the drug aseptically during assembly. Such manufacturing processes may be costly since the entire process must be kept sterile and because the fill and assembly lines need to be specially-tailored for the device. Accordingly, this adds substantial operating costs to pharmaceutical companies and contract drug-fillers.
Drug delivery devices are generally prepared by molding or shaping the various components and then assembling the components. The assembling steps and other processing operations typically produce a device that subsequently must be cleaned to remove particulates adhering to the surfaces to satisfy cleanliness standards for drug delivery devices. After cleaning, conventional drug delivery devices are packaged and sterilized. Such delivery devices have been classified into several general types. The first type is assembled and placed in sterile packaging which can be shipped with a vial or ampoule of a drug or other injectable solution. The vial or ampoule is generally made of glass or other clear material that does not interfere with the stability of the drug during prolonged storage. The delivery device is filled with the drug or other solution at the point of use and injected into the patient. These devices have the disadvantage of increasing the time and difficulty of filling the device at the point of use with increased possibility of contamination of the delivery device and/or drug solution. There is a further risk of glass particles from the ampoules contaminating the drug solution when the ampoules are opened.
Several of these disadvantages are overcome by providing prefilled delivery devices which can be filled with a suitable drug solution prior to use. Prefilled delivery devices, as the term is known in the art, are devices that are filled by the drug manufacturer and shipped to the health care provider or self-administering patient in a condition that is ready for use. Prefilled delivery devices have the advantage of convenience and ease of application with reduced risk of contamination of the drug solution. Prefilled drug delivery devices are generally assembled and packaged in clean rooms to maintain proper cleanliness levels. The clean rooms are equipped with extensive filter assemblies and air control systems to remove particulates and pyrogens from the air in the room and to prevent particulates and pyrogens from entering the room. The operators and other personnel in the clean room are required to wear appropriate protective garments to reduce contamination of the air and the drug delivery devices being manufactured or assembled. As people and equipment enter and leave the clean room, the risk of contamination and introduction of foreign particulates and pyrogens increases. Various operations are able to form clean and sterile drug delivery devices. However, subsequent handling, filling and printing of the drug delivery device can contaminate the device. It is then necessary to clean and sterilize such conventional drug delivery devices before use. Accordingly, there is a continuing need in the industry for an improved system for manufacturing and assembling clean and sterile medical devices and filling such devices.